Separable fastening devices are currently used widely in a great number of applications. Articles which are repeatedly opened and closed are examples of situations in which it is desirable to employ separable, or releasable, fastening devices. Certain packages, for instance, require a closure which permits periodic access to the package contents and will be held closed during the remaining periods. Other uses of separable fastening devices include those uses which are incorporated into clothing, disposable articles, and various miscellaneous articles such as safety belts and the like in which it is desirable to create a releasable bond between two or more articles or between several surfaces of the same article. In certain applications, these prior separable fastening devices have replaced conventional buckles, zippers, buttons, snaps, tie fasteners, and sewing.
Virtually all of the prior separable fastening systems can generally be categorized as either mechanical fastening systems or adhesive fastening systems. Mechanical fastening systems, or mechanical fasteners, are those in which a releasable mechanical bond is formed between the components of the fastening system. Adhesive fasteners utilize the adhesive properties, or the tackiness of the surfaces of one or more of their components to adhere to another surface to create a releasable bond. Despite the relatively wide acceptance of the two types of separable fastening devices, as discussed below, both types suffer from a number of drawbacks.
In most of the separable mechanical fastening systems currently in use, the mechanical bond formed between the components of the device is achieved by some type of entanglement between the component parts of the system. A popular type of mechanical fastener currently in wide use which utilizes mechanical entanglement to create a separable bond is sold under the trademark "VELCRO". VELCRO fastening devices are described in greater detail in U.S. Pat. No. 2,717,437 and U.S. Pat. No. 3,009,235 issued to George de Mestral. Briefly, VELCRO fasteners utilize two components, a male component and a female component. The male and female components are often referred to as the hook and loop components, respectively. The hook component consists of a fabric which contains a plurality of resilient, upstanding hook-shaped elements. The other component or part of the fastening system consists of a fabric which contains a plurality of upstanding loops on its surface. When the hook component and the loop component are pressed together in a face-to-face relationship to close the fastening system, the hooks entangle the loops to form a plurality of mechanical bonds between the individual hooks and loops. When the two components are pressed together to create these mechanical bonds, the components will not generally disengage under normal conditions. Should it be necessary to open this hook and loop type fastening system, it is very difficult to separate the components by attempting to disengage all of the hooks at once. However, when a gradual peeling force is applied to the hook component, disengagement can be easily effected since the hooks, which are comprised of a resilient material, will readily open when subjected to peeling forces.
Despite adequately serving their purpose of providing a generally reliable separable mechanical bond, the VELCRO-type mechanical fastening systems suffer from a number of drawbacks. When the male and female components of the commercially available version of the VELCRO fastening system are peeled apart, the disengagement of the hook and loop components creates a rather loud, harsh ripping noise. This is particularly undesirable in the case of one of the uses contemplated by the present invention where is is desirable to provide a separable fastening device for use in personal care situations, as in for instance, use in a personal package of facial tissues. Also, due to the fact that it is necessary to form the minute hook and loop elements, mechanical fastening devices, such as VELCRO, are relatively expensive to manufacture. This later disadvantage makes them generally undesirable for use as fasteners in disposable articles, that is, articles which are generally discarded after a single use.
The majority of adhesive separable fastening devices have been in use for a considerable period of time and have not changed significantly, as a result, most can be categorized in generic terms. An example of such a separable adhesive fastening device is one which employs a pressure sensitive adhesive material as one of its components. The primary disadvantage of pressure sensitive materials, and other devices which employ the conventional tacky or sticky surfaces to create a separable bond between two articles is that such surfaces are prone to contamination by, among other things, dirt, lint, dust, and the like, all of which tend to reduce the adhesive properties of the fastener. Eventually this loss of the adhesiveness will result in the rendering of the fastener completely useless for its intended purpose.
As a result of the foregoing, a need exists for an improved separable fastening system which overcomes the drawbacks inherent in the separable fastening devices currently in use.
Therefore, it is an object of the present invention to provide a separable fastening device which is capable of opening and closing more quietly than previously used mechanical fastening devices.
It is another object of the present invention to provide a separable fastening device which does not employ conventional adhesive surfaces which are subject to contamination and consequent loss of their adhesive properties.
It is also an object of the present invention to provide a separable fastening system which is inexpensive and simple to manufacture.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in conjunction with the accompanying drawings.